SRAM has long been a popular choice for use as fast memory. For this reason, SRAM is often used as cache memory in computer systems, e.g., personal computers (PCs) and workstations. SRAM is markedly faster than dynamic random-access memory (DRAM), because it does not need to be refreshed, and dramatically faster than a hard drive, because reading from it does not require mechanical action.
Various approaches have been undertaken to increase SRAM speed. One approach involves improving memory bitcell switching speed. Another approach involves employing current sensing for large SRAM arrays. Yet another approach involves precharging bit lines to a level lower than VDD. All of these techniques hold promise.